Fix codecov coverage badge in readme (#3024)

Summary:
At the time #3023 was created, codecov had not yet updated its urls internally. This has happened now and now the coverage badge is broken. This updates the relevant urls to fix that.

Pull Request resolved: #3024

Reviewed By: saitcakmak

Differential Revision: D83256946

Pulled By: Balandat

fbshipit-source-id: 525314fa6935d2a5c5c756db428dacf6d150ec52

Author: Balandat

README.md

@@ -9,7 +9,7 @@
 [![Test](https://github.com/meta-pytorch/botorch/workflows/Test/badge.svg)](https://github.com/meta-pytorch/botorch/actions?query=workflow%3ATest)
 [![Docs](https://github.com/meta-pytorch/botorch/workflows/Docs/badge.svg)](https://github.com/meta-pytorch/botorch/actions?query=workflow%3ADocs)
 [![Nightly](https://github.com/meta-pytorch/botorch/actions/workflows/nightly.yml/badge.svg)](https://github.com/meta-pytorch/botorch/actions?query=workflow%3ANightly)
-[![Codecov](https://img.shields.io/codecov/c/github/pytorch/botorch.svg)](https://codecov.io/github/pytorch/botorch)
+[![Codecov](https://img.shields.io/codecov/c/github/meta-pytorch/botorch.svg)](https://codecov.io/github/meta-pytorch/botorch)
 
 [![PyPI](https://img.shields.io/pypi/v/botorch.svg)](https://pypi.org/project/botorch)
 [![License](https://img.shields.io/badge/license-MIT-green.svg)](LICENSE)